This invention relates to a mount for adjustably mounting an elongated luminaire, or an elongated system of such luminaires, to a wall, a ceiling or other mounting surface.
It is common to mount elongated luminaires, such as those having elongated reflectors housing elongated light sources including fluorescent tubes, on surfaces such as walls and ceilings, using brackets rotatably fastened to the ends of the reflectors. The rotational fastening allows for adjustability of the luminaire about its longitudinal axis, so that the light produced can be aimed properly at the desired surface or subject.
Once the luminaire is properly aimed, it is desirable to lock it in place rotationally, to prevent the aim from slipping. In previously known luminaires, such rotational locking of a luminaire about the long axis of its elongated reflector generally was accomplished by tightening a fulcrum screw and nut used to attach the reflector to the mounting brackets. However, normal luminaire use, as well as ambient vibrations, would sometimes cause the screw and nut to become loose and the reflector to rotate out of its desired position.
Additionally, certain lighting applications require luminaires with elongated reflectors to be mounted adjacently, end-to-end, in elongated systems of elongated luminaires. If such mounting is achieved using screws, nuts and brackets as described above, the resulting configuration generally produces dark spots in the lighting pattern on an adjacent ceiling or wall near the location at which one lamp ends and the next lamp begins. Such dark spots are caused by the large end-of-lamp intervals necessarily found in mounting configurations such as that described above. For example, in some previously known luminaires, the end-of-lamp intervals (space between lighted portions of lamps) are approximately three and one-half inches.
An alternative mounting configuration is described in commonly-assigned U.S. Pat. No. 4,881,156, which is hereby incorporated by reference in its entirety. In the configuration described in that patent, adjacent reflectors are attached to two separate, but closely spaced, parallel arms of a single mounting bracket, allowing the ends to be closer together. To minimize the distance between the arms while still providing for rotational locking of the reflectors, separate locking clamps are provided to clamp each reflector to is respective arm. The locking clamps are accessible from inside each reflector, eliminating the need to space the arms farther apart to allow access.
The luminaire configuration described in said above-incorporated U.S. Pat. No. 4,881,156 is not without its own disadvantages. Although the lamps are closer together, there are still some perceptible dark spots in the lighting pattern. Moreover, the large number of parts, such as in the locking clamps, complicates installation of the luminaires. In addition, harsh vibrations can still adversely affect the rotational locking.
It would therefore be desirable to be able to provide an adjustable luminaire or luminaire system, and a respective adjustable mount or mounting system therefor, that would further minimize dark spots in the lighting pattern, while allowing easy installation and adjustment, and providing a more effective braking mechanism, as compared to previously known systems.